Method and apparatus for gravelpacking wells



2 Sheets-Sheet 1 J. E. ECKEL ET AL Filed June 2, 1959 METHOD AND APPARATUS FOR GRAVEL-PACKING WELLS Dec. 10, 1940.

M2? ATTORNEY.

wfg INVENTOR BY W@ Dec. 10, 1940. 2,224,538

METHOD AND APPARATUS FOR GRAVEL-PACKING WELLS.

J. E. ECKEL' ET AL Filed June 2, 1939 2 Sheets-Sheet 2 5 lNvENToR pf. @i767 ATTORNEY.

0 which is adapted to be used in carrying out the Patented Dec. 10, 1940 PATENT OFFICE METHOD AND APPARATUS yFOR. GRAVEL- 'PACKING WELLS John E. Eckel and Carl E. Reistle, Jr., Houston,

Tex., assignors to Standard Oil Developmentl Company, a corporation of Delaware Application June 2, 1939, Serial No. 276,940 11 claims. (Cl. 16e-21) '\I'he present invention relates to a process and ap aratus for forming a cavity in a bore hole and for placing gravel or like material into the cavity formed.

It\v is known to the art to set a screen into the production zone of a well, to form a cavity around the screen and to ll the cavity with gravel. The herelndescribed invention is an improved method for washing out a cavity and placing gravel in the cavitylv around the screen and apparatus for carrying out theabove described improvement.

More specifically, the invention involves ttin'g tubin/g with a valve, a screen and a setshoe, the valve containing side ports and being located in the tubing at a point above the screen and setshoe. The tubing fitted as above described is t en lowered into a bore hole until the screen )g at a producing level. A Wash liquid is then .forced down4 the tubing and out through an aperture in the setshoe into the bore hole. The wash liquid passes upwardly around the strainer, and since it has a relatively high velocity it washes solids loose from around the strainer, and as it flows upwardly inthe space between the casing and theside of the hole, it carries the entrained solids which have been washed loose. We call this the method of washing byfnormal circulation. In this washing step not only a portion of the producing formation, but also drilling mud and other matter which may have been deposited in the hole during the drilling is removedv to form a cavity.

When a cavity of suitable size has been formed by washing, the valve in the tubing is opened by dropping a ball or plunger down the tubing, and then liquid carrying entrained gravel is forced down the tubing and out the opened side ports of the valve and into the previously formed cavity. The velocity of the liquid is diminished and its direction of flow is changed as it passes into the cavity, and the reduction in velocity and change in direction of ow of the liquid allows the entrained gravel to settle to the desired position in the cavity. 4

The invention involves the above described procedure for Washing out a cavity and placing gravel therein, apparatus for carrying out the washing out and graveling operation, and a valve operated by means of a drop ball or plunger above described procedure.

Further objects and advantages of the present invention will appear from the following description of the accompanying drawings in which:

Fig. 1 isa vertical sectional view through a casing in a bore hole in which a tubing equipped with a valve, screen and setshoe has been lowered. The valve is shown in its closed position;

Fig. 2 is a view of the apparatus shown in Fig. l showing a plunger being dropped down the tubing to operate the valve in the tubing;

Fig. 3 is a cut showing the valve illustrated in Figs. 1 and 2 after the plunger has struck the inner sleeve of the valve and has caused it to open; and

Fig. 4 is a cut similar to Fig. 3 and shows modications of the apparatus illustrated in the preceding figure. v

In Fig. 1, numeral I designates a casing set in a bore hole and numeral 2 designates a conventional cement plug at the bottom of the casing. Lowered into the casing is tubing 3 at the` bottom of which is attached setshoe 4 containing back pressure valve 5. Attached to setshoe 4 is screen 6, the top opening of which is closed by shoulder 'I which is attached to the tubing. At a point in the tubing above the screen is a. valve 8 which is formed as follows:

An outside sleeve 9 containing ports I0 is fitted with an inside sleeve II which ts slidingly in outside sleeve 9 and operates to open andclose the side ports I0 of the valve. Outside sleeve 9 contains a projection or shoulder I2 at a point -above ports I0 to control the upward movement of inside sleeve II. The downward movement of inside sleeve II is controlled by the upper portion of member I3 which is attached to outside sleeve 9 by screw threads and by coil spring I4 which is supported by member I3 and which acts to keep inside sleeve I'I in its upper-most position. Attached to the tubing at a point above valve 8 is a projection IS- and a centering guide I1. t

The apparatus is used in the following manner: After the casing is cemented in the well in the conventional manner, the apparatus is assembled with the tubing 3 attached to setshoe 4 by left hand threads or other suitable releasing means. Outside the tubing and attached to theA upper end of the setshoe is screen 6, the top of the opening between the screen and the tubing being closed by shoulder 1 which keeps materials from falling through the opening as the appara-` tus is lowered into the well. The above described valve 8 is attached in the tubing at some point above the screen, and centering guides I'I are attached to the tubing above the valve. The apparatus is then lowered at the end ofa string of tubing into a bore hole until the shoe rests on the bottom of the hole with the screen at a producing level. A wash liquid which. may, -for'ex- 55 ample, be oil or water, depending upon the varying` circumstances, as is well known in the art, is then pumped into the tubing string and passes out of the back pressure valve 5 of thesetshoe and into the bottom of the hole. The wash liquid washes sand and like material out of the bottom of the hole and up out of the hole between the tubing and the casing, thus forming a cavity in the producing zone.

After a suiciently large cavity has been formed, ball I5 is dropped into the upper end of the tubing and falls through the tubing as shown by Fig. 2. The ball falls through` the outside sleeve 9 and strikes the inside sleeve II closing of! the bottom of sleeve II and the liquid pressure above it causes sleeve II to compress spring I4, moving the sleeve downwardly and opening the valve, as shown in Fig. 3. Liquid carrying entrained gravel is now pumped down through the tubing and out through open ports I into the cavity which has been previously formed. Projection IB causes material passing out through ports II) to make a sharp change in direction, in order to pass upwardly between the tubing and casing.

` As liquid containing gravel passes into the cavity,

the reduced velocity of the liquid as well as its changed direction causes the gravel to drop downA posited gravel into the screen to enter the bottomof the tubing and flow upwardly therethrough. The fiow of liquid in this direction opens the valve and allows the liquid to be removed from the producing zone of the well.

The modification shown in Fig. 4 shows a strainer I8 substituted for the projection I6 of Fig. 1. This strainer acts to reduce the velocity of the liquid flowing upwardly between the tubing and the casing and assures that gravel will not pass upwardly with the liquid. In Fig. 4 is also ,shown a closure I9 which may be substituted for the ball I shown in Figs. 1, 2 and 3. While, as above disclosed, liquid passes upwardly through the tubing 3 While the well is producing it may on some occasions be advantageous to remove the closure from the tubing. In such cases, thesides the two modifications shown in the draw--` ings may be used.

JManifestly, other means for causing the above described valve to open may be employed. For

example, a shear pin may be used to hold the valve in a closed position, such a size of pin being selected that, when the plunger is dropped down the tubing and strikes the valve, the pin hole is well known to the art and when used in the above described procedure, is carried out in the conventional manner. When this procedure is employed, the washing step is used principally for washing off from the face of the producing 5 formation the layer of mud formed thereon during the underreaming step. f

Obviously, the specific embodiments described above are merely illustrative of the present invention which is not limited thereto, but only 10 by the appended claims in which it is intended to 'claim thefpresent invention as broadly as the prior art permits.,

We claim:

1. Apparatus for application to a well comprising, in combination, atubular screen, a setshoe attached to the lower end of said screen, and a string of tubing adapted tobe lowered into the screen and attached to the setshoe, said tubing being fitted with a valve at a point above the screen which may be opened at will and, when opened, causes a discharge from the sides of the tubing ata point above the screen.

2. Apparatus for placing gravel at a producing level of a well comprising tubing fitted with a valve provided with side ports, the valve operating to open the side ports when a plunger dropped down the tubing strikes the valve.

3. Apparatus for washing a cavity around a tubular screen set at a producing level and for depositing gravel in the cavity comprising a setshoe containing a backpressure valve attached to the lower end of the screen, tubing fitting inside the screen and. attached to the setshoe, said tubing being fitted with a valve containing y side ports at a point above the screen which operates to open said side ports when a plunger is dropped down the tubing and strikes the valve.

4. A process for Washing out a cavity around a screen set at a producing level of a bore hole and for depositing gravel in the cavity comprising the steps of lowering tubing fitted with a screen and a setshoe containing a backpressure valve into a bore hole, forcing liquid out ofthe tubing at a point below the screen to wash out a cavity, closing off the tubing at a point above the screen and at the same time opening ports located in the tubing at a point above the screen and forcing gravel into the tubing and out through said ports into the cavity, the general direction of travel of the gravel being opposite that of the material removed in forming the cavity.

5. A process as in claim 4 in which both drilling mud and producing formation is removed in washing out the cavity.

6. A valve adapted for use in the lower end of a string of tubing in washing and graveling a bore hole comprising an outside sleeve having its interior fitted with a shoulder and containing vports in its walls, an inside sleeve fitting inside the outside sleeve and moving slidingly therein,

-the sleeve and ports being so arranged that,

when the inside sleeve rests against the shoulder of the outside sleeve, it closes the ports, and when it slides away from this position, it opens the ports, a member Aattached to the outside sleeve adapted to retain a spring fitting inside the outside sleeve in the space betweenthe member and the inside sleeve, and a member adapted to slide freely in the outside sleeve to open the side ports of the valve when it strikes the inside sleeve.

7. A process comprising the steps of setting a screen in a' bore hole, forcing liquid into the 75 bore hole at a point below the screen and washing material up around the screen and out of the bore hole, thus forming a cavity around the screen, then forcing gravel into the bore hole at a point above the screen so that it drops into the cavity around the screen.

8. A valve adapted for use in the lower end of a string of tubing in washing and graveling a bore hole comprising an outside sleeve containing ports, an inside sleeve tting slidingly inside the outside sleeve, and means to retain the inside sleeve in such a relation with the outside sleeve as to keep the ports closed until the pressure in the tubing reaches a predetermined amount, and to allow the inside sleeve to uncover the ports when the pressure in the tubing reaches said predetermined amount.

9. A method of completing a well comprising the steps of placing a screen at the bottom of a bore hole, establishing liquid circulation out through an opening in the bottom of said screen and upwardly around said screen to form a cavity and remove foreign matter from around the screen, then diverting circulation above said screen to introduce and deposit gravel around said screen, then stopping the circulation of liquid downwardly into the bore hole and allowing liquid from the formation adjacent the cavity to now through said gravel and screen and upwardly through said bore hole to the surface of the earth.

10. A method of completing a well wherein all of the operations are performed by control from the surface requiring only an initial trip in the holecomprising the steps of lowering into a bore hole a screen attached to a stringof pipe, said and screen and up around the screen to form a cavity and remove foreign matter from around said screen, closing said valve above the screen and diverting circulation through the Side ports and introducing and depositing gravel around said screen, then closing said side ports and opening said valve to permit fluid from the formation to flow through said gravel, screen and valve upwardly through said pipe to the surface.

11. A valve controllable from the surface adapted for use in a string of tubing in a bore hole comprising an outside sleeve having its interior fitted with a shoulder and containing ports in its walls, an inside sleeve fitting inside the outside sleeve and moving slidinglytherein, the sleeve and ports being so arranged that, when the inside sleeve rests against the shoulder of the outside sleeve, it closes the ports, and when it slides away from this position, it opens the ports, a member attached to the outside sleeve adapted to retain a spring fitting inside the outside sleeve in the space between the member and the inside sleeve, and a member adapted to slide'freely in the outside sleeve and to open the side ports of the valve when it strikes the inside sleeve, said member being placed within said tubing at the surface and positioned within said inside sleeve by the force of gravity and uid pressure within the tubing.

JOHN E. ECKEL. C. E. REISTLE, JR. 

